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INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2022
Operating Loss Carryforwards [Line Items] |  |  |  |
Tax rate reconciliation, disallowed loss on sale of business | $ 4,219 |  |  |
Tax rate reconciliation, disallowed goodwill impairment | 3,001 |  |  |
Tax benefit of nontaxable solar manufacturing credits | 12,258 | $ 18,972 |  |
State income tax expense |  | 12,805 | $ 21,630 |
Tax rate reconciliation, tax benefit from share-based compensation |  | 13,773 |  |
Tax rate reconciliation, solar tax credits |  |  | 39,493 |
Unrecognized tax benefits | 4,517 | 3,367 | 2,581 | $ 985
Accrued interest and penalties | 648 | 516 |  |
Unrecognized tax benefits, increase (decrease) | 1,332 | 1,370 | 1,792 |
Increase (decrease) of unrecognized tax benefits related to various state jurisdictions' uncertain tax positions | (182) | (585) | (196) |
Increase (decrease) of accrued penalties and interest for uncertain tax positions | 132 | $ 281 | $ 158 |
Undistributed income | 182,176 |  |  |
Federal |  |  |  |
Operating Loss Carryforwards [Line Items] |  |  |  |
Operating loss carrying forwards | 24,687 |  |  |
Non-U.S. |  |  |  |
Operating Loss Carryforwards [Line Items] |  |  |  |
Operating loss carrying forwards | $ 73,879 |  |  |
Operating loss carryforwards expiration term (year) | 5 years |  |  |

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